Backfill a new archive

Before completing the following procedures, be sure to complete the steps in Prepare Data Archive for backfilling.

Note: By default, data is compressed. If you do not want compression, disable the Snapshot_DoNotReplacePTCreatedOnOOO tuning parameter.

1. Install Data Archive, start the Data Archive server, create all points, and then stop the Data Archive server.

2. Isolate the Data Archive server from all incoming process data.

   To do this, follow one of these methods:

   • Shut down PI interfaces on all PI API and PINet nodes.

   • Disallow all PI API connections at the server. Start piconfig without starting Data Archive. Disregard messages about failure to connect and enter:

     @table pifirewall
     @mode edit,t
     @istr hostmask,value
     "*.*.*.*",DISALLOW

     Note: Entries that allow access to specific names or addresses override the DISALLOW option. Edit all other entries to DISALLOW. Local connections are not affected by PIFirewall table entries; verify that applications that may write data are not running.

3. Start the Data Archive server with the -base parameter. This ensures that Data Archive starts up with only the minimum required subsystems. Enter the command:

   pisrvstart.bat -base

4. Use piartool -acd to create and register one or more archive files for the backfilling period. You can also use the Archives tool in PI SMT to create multiple files for backfilling. For more information, see Create multiple archives for backfilling.

5. If the Snapshot_DoNotReplacePTCreatedOnOOO parameter is enabled, delete all the Pt Created events from the snapshot. For more information, see Work with Point Created snapshots.

6. Depending on whether you are using compression, do one of the following:

   • To backfill with compression, send the source data in time-sequential order with the oldest data first.

     Note: Make sure that data sources are not writing to any points that are being backfilled. Otherwise, compression is bypassed for data that is written prior to the snapshot time.

   • To backfill without compression, specify the start time as the time stamp of the oldest data to be backfilled; and specify the end time as the start time of the oldest archive as listed by piartool -al. The data that you backfill is not compressed, since the start time of the oldest archive occurs prior to the snapshot time.

     If, after backfilling has started, you discover that the backfill archive requires more than 2 TB of disk space, delete the backfill archive and create multiple dynamic archives to store the data. Divide the target time range between the dynamic archives, and then retry the data backfilling.

7. If you used the technique of modifying the PIFirewall table in step 2 above, run piconfig to either change the hostmask value to ALLOW or delete the hostmask.

8. Start the remaining Data Archive applications by running pisrvstart.bat without the -base flag.